1. Field of the invention
This invention relates to control apparatus for a closed transport system comprising a plurality of routes, a plurality of route junctions which each allow a choice of two directions and at least one vehicle arranged to travel along the routes. More particularly the invention relates to apparatus for controlling passage of at least one vehicle through the system to a destination route segment.
The invention may be used with transport systems which are sub-divided into a plurality of interconnected networks, or with systems which are not so divided. In the following description the term "division" is used to denote a directional decision junction within a network, and the term "branch" is used to denote a directional decision junction where a network is connected to an adjacent network of the system.
Such a transport system can be equipped with rails and with divisions and/or branches which are set in a predetermined direction and can be changed into another direction, or it can be rail-less, having marked paths to guide the vehicles, which paths are defined either by guide rails, if required inserted in the floor, or by cables laid below the floor and which develop an electromagnetic field which effects control means on the vehicles, which are equipped with suitable receiving equipment. Optical paths can also be used, control being effected by stroboscopic rays which are reflected by mirrors on the vehicles. In a rail-less embodiment, the vehicle may have a steering device which is set up in a certain way in the branches and leads the vehicle to the chosen course by known control means.
2. Description of the prior art
In the last method an arrangement of markings on the path of movement is known, for example in the form of magnetic or electromagnetic fields or in the form of mechanical profiles, which are detected by a probe on the vehicle, whereby on the vehicle a recording apparatus records the number of markings and after a certain number gives a steering signal.
Such apparatus has already been proposed in German Patent Application P 15 30 894.
Furthermore, a vehicle according to German Patent Application P 19 55 758 can be adapted for use in an embodiment of the present invention.
These known methods require an important part of the control apparatus in the vehicle. Moreover, in these methods, the path is marked passively, so that the whole control coding must be recorded in the vehicle, particularly as it alters, according to the point from which a vehicle departs. The range of application of such control apparatus is thus limited.
A further disadvantage of such control apparatus is the inflexibility of the system. Alterations in the system or completion of the system require major alteration in the recording devices of the vehicles or cannot be carried out at all without altering the whole system.
Furthermore, in these known apparatuses it is impossible to remove a vehicle from the path of travel and guide it again into the path of travel at another place, since control of its path is obtained by recording elements in the path of movement in order to reach the predetermined destination or goal.